<descriptor thcode="62"><thesaurus thcode="62" name="Coastal and Marine Ecological Classification Standard" scope="Categories of ecosystems for coastal, estuarine, and marine environments." creator="FGDC" rights="public domain" date="2017-05-10" codetype="alpha" prefix="cmecs" uri="https://www2.usgs.gov/science/CMECS" tblname="cmecs" root_code="root" contact="pschweitzer"><category><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/></category><altlabel><altlabel>CMECS</altlabel><altlabel>CMECS</altlabel><altlabel>Coastal and Marine Ecological Classification Standard (CMECS)</altlabel><altlabel>Coastal and Marine Ecological Classification Standard (CMECS)</altlabel></altlabel></thesaurus><term thcode="62" code="SC-316" name="Organic Mud" parent="SC-304" scope="Substrate Subclass: Unconsolidated organic substrate with a median particle size of less than 0.0625 millimeters (Silts, Clays, and Muds), and an organic carbon content of greater than 5%."/><bt><term thcode="62" code="SC-304" name="Organic Substrate" parent="SC-301" scope="Substrate Class: Surface layers of substrate are primarily composed of non-living organic material, including fine or coarse organic particles up to 4,096 millimeters in any dimension. ..."/><term thcode="62" code="SC-301" name="Biogenic Substrate" parent="SC-C003" scope="Substrate Origin: Substrates where percent cover of non-living Biogenic Substrate exceeds percent cover of both Geologic Substrate and Anthropogenic Substrates, when all are considered separately. ..."/><term thcode="62" code="SC-C003" name="Substrate" parent="root"/><term thcode="62" code="root" name="CMECS" scope="Coastal and Marine Ecological Classification Standard: Category terms encompassing waters from the head of tide or inland incursion of ocean salinity to the splash zone of the coasts to the deepest portions of the oceans and the deep waters of the Great Lakes."/></bt></descriptor>